Never Know What You'll Find On A Leisurely Dive

When scuba diving in Hong Kong, you see numerous nudibranchs, poisonous pufferfish, and the odd octopus. On September 14, my buddy and I spotted something different: a submerged World War II bomb.

I posted a photo on Facebook, hoping someone could determine if the device was an unexploded bomb, a practice bomb, or something else. Within 30 minutes, an officer of the Hong Kong Police's Explosive Ordnance Disposal (EOD) Bureau contacted me.

Over the next week, I answered questions about the suspected bomb and its location and shared more photos of the device. The EOD officer said it could be a 500-pound U.S. aerial bomb containing up to 267 pounds of TNT. On land, it could produce a blast radius of more than 1,500 meters. The officer asked if I could join a team of police divers in a search operation. I agreed. But could I find the bomb again?

Locating the Submerged UXO

Visibility varies in Hong Kong waters. On a good day, 10 meters is possible. But 50 centimeters is not unusual. After some eight decades, the suspected bomb was camouflaged with layers of marine life. It was also sitting at 13 meters, where less than 16 percent of the sunlight penetrates, making underwater searches difficult. Despite these challenges, I was confident.

On my initial dive, I took a GPS reading and surface photos and photographed the suspected bomb with my Olympus TG-5.

With this data, I determined the dive's approximate starting point and direction, confirmed the coordinates with surface landmarks, and estimated its location and depth. That seemed like a good start.

The Search Begins

On the morning of September 23, the EOD team drove me to Hung Hom to meet the police divers. I wasn't surprised when asked to show my certification cards and quizzed about my experience. As the police divers explained, they were responsible for my safety and their own.

The police planned two dives, each with a maximum bottom time of one hour. Our first dive lasted 16 minutes. We surfaced for two minutes so the divers could confer and submerged again to resume the search. Ten minutes later, we found the bomb. After fist bumps, the police divers attached a delayed surface marker buoy (DSMB) to a reel and lead weight and shot to the surface, indicating the bomb's location.

We climbed aboard the launch and made way for a team of EOD divers to confirm we had discovered a bomb and record its location.

On the afternoon of October 8, the police used a controlled explosion to destroy the unexploded bomb, which they identified as a 500-pound Japanese aerial bomb from World War II.

During the Japanese occupation (December 25, 1941-August 15, 1945), American aviators dropped thousands of bombs on Hong Kong. In a single eighthour raid on January 16, 1945, nearly 500 aircraft dropped 154 tons of bombs on Japanese ships, as well as docks and refineries, mainly around Victoria Harbor. It's been nearly 80 years since the end of WWII, but unexploded ordnance is still being discovered, as my story relates.

Christopher Dillon chaired the Hong Kong-based South China Diving Club from 2018 to 2020.